Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Manassas can be used to estimate when you can plant cosmos.

Planting Calendar for Cosmos

Frost tolerance for cosmos:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Cosmos can survive in mild cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant cosmos in Manassas is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant cosmos and expect a good harvest is probably August. Any later than that and your cosmos may not have a chance to really do well. Starting your cosmos indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Manassas. You can expect an average low temperature of 0°F in the coldest months of winter.

Remember that USDA zone info for Manassas is an average and the actual date of last frost will vary from year to year. Since half of the time in Manassas last frost occurs after April 15 be ready to cover your cosmos if you have a surprise late frost.

USDA Zone Info for Manassas

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Manassas

You may be interested in your other planting guides for Manassas.